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Help! Oil in water

PhilL

Active Member
Joined
Aug 31, 2003
Messages
81
Location
Bristol
Car
2002 SL500; '54 E270 CDI Elegance Estate; 2001 C200K Coupe
I’m new to the club and this is my first cry for help.

I have a continuing problem with oil in the expansion tank on my 1990 300TE (130k).

The car was laid up for more than a year and once back on the road the coolant became emulsified oil. The head was removed and indications were that a leak had developed behind No4 cylinder between high pressure oilway and water jacket. The head was checked with a straight edge and reassembled with new head gasket. Coolant flushed repeatedly and car back on road.

Soon after, problem back. Head off again, skimmed and reassembled with new gasket and head bolts. That was over a year ago and I’m still mopping oil from the expansion tank each week. Oil level does drop but only very slowly, not a problem.

All work carried out following genuine MB workshop manuals. Yes I have a set!

Has anyone out there had similar problems so that we can share our experiences?

Despite the problems the car is still my favourite and remains a pleasure to own and drive.
 
You say you are still mopping oil from expansion tank?? How much, is it just a film on the top of the water or more?

Also have you used the car much since you skimmed the head, or is it standing around?
 
Boss had this on his 300SL

Garage did the headgasket - then it happened again - I took a look and diagnosed radiator :)

Auto box cooler in the rad had developed a perforation - and this was causing the transmission fluid to be forced into the cooling system

Its certainly worth a look - it might be autobox fluid - not engine oil!

HTH

Mark
 
Thanks for the reply Brian, the oil is only a film on the top of the water which I remove by dipping kitchen towel in to catch the oil, takes about three sheets each week! The car is regularly used by the wife for short journeys.

Mark, never thought of radiator oil, maybe I should check the level.

Another thought! What if the oil pressure is going too high. Is it possible to check the operation of the pressure relief valve?

Thanks again
 
Phil

As it is only a thin regular film of oil, I would be inclined to wash out your system again using a proper flushing agent, not plain water. Oil residues are very difficult to shift from nooks and crannies in the engine block and pipework.

Marks radiator suggestion needs eliminating first though.

Good luck.
 
Mark

Thanks for the suggestion. I'll give it a good flushing when time permits and let you know the outcome in due course.

Any other comments would be welocomed!

Phil
 
if you change your head gasket you still have some oil in the water tank u can can flush the system 10 times but u can still see oil in the water tank if it starts to over heat then you have a problem
 
Thanks for the reply 2swift4u. Its reassuring to hear from you and others that it may only be residue in the engine rather than more problems. Please keep the confidence boosters coming.

I'll try a good flush when time permits.
 
oil in water

just read the posts on here and think i should share my experience...

on 15th april 08 i took delivery of a brand new 7.5 ton truck (i wont state what make but i had 6k mods done to the cab and in total cost me a few pennies short of 50k)

after 4 weeks i noticed oil in the header tank and immediately took it back to the main dealer.

it has (seemingly)been flushed several times but i still see a build up of gunk on the underside of the cap and a film on the water and all over the inner side of the header tank.

i am a one man band and this is a VERY big investment for me. i'm very worried as they are telling me all is ok and no harm will be done and i'll never get all the oil out of the cooling system.

i feel like my brand new lorry is contaminated and i cant do anything about it. what i am worried about is further down the line if i have problems then these could be caused by this ? .. how am i to know? what are the possoible problems ??

many thanks
 
The MB E-class owner's bible says:

"If the leak is into the cooling system, then, in addition to replacing the head gasket, the cooling system must be thoroughly cleaned. Without proper cleaning, oil will saturate the cooling-system hoses, making them soft and prone to bursting. . . . use MB part no. 001 986 21 71. Using a 3% solution works well. Run the engine for 10 minutes before completely flushing the cleaner out of the system with clear water. The heater must be on and running to clear the oil from the heater core."
 
just read the posts on here and think i should share my experience...

on 15th april 08 i took delivery of a brand new 7.5 ton truck (i wont state what make but i had 6k mods done to the cab and in total cost me a few pennies short of 50k)

after 4 weeks i noticed oil in the header tank and immediately took it back to the main dealer.

it has (seemingly)been flushed several times but i still see a build up of gunk on the underside of the cap and a film on the water and all over the inner side of the header tank.

i am a one man band and this is a VERY big investment for me. i'm very worried as they are telling me all is ok and no harm will be done and i'll never get all the oil out of the cooling system.

i feel like my brand new lorry is contaminated and i cant do anything about it. what i am worried about is further down the line if i have problems then these could be caused by this ? .. how am i to know? what are the possoible problems ??

many thanks

Perhaps you should be asking this on a forum dealing with your make and model of truck? It might be a fault common to a particular production run of engines. Is it a Mercedes and what engine has it got? If its a new truck there should no question of any oil in the water. Are you sure you are not mistaking oil for anti freeze? The build up of an oil emulsion under the filler cap might be due to cold running-did the engine have a thermostat fitted? Since this vehicle represents a considerable investment on your part I would seriously consider hiring a third party professional engineer to report on it. If he finds that the engine has this fault I would be pressing the manufacturer for a new engine.
 
Was the head gasket or other part changed, and was a fault actually diagnosed?
If there is oil in the water then there is a problem, but it could just be residue although that wouldn't normally keep making emulsion on the cap.

Is there any evidence of water in the oil.?
 

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